1. Field of the Invention
The present invention relates generally to the field of vehicles used for removing coatings from surfaces. More specifically, the present invention discloses a coating removal vehicle equipped with an inflatable suction ring that can be quickly and easily reversed or replaced in the field to minimize downtime.
2. Statement of the Problem
Various types of crawlers have long been used for cleaning or removing coatings from surfaces. For example, magnetic crawlers are sometimes used in cleaning and painting the hulls of ships. These vehicles typically have caterpillar tracks with a series of magnets spaced along their periphery that hold the vehicle to the ship hull. The tracks are propelled by means of hydraulic, pneumatic, or electric motors to move the vehicle along the hull. The frame of such devices can be used to carry sandblasting equipment, spray nozzles for cleaning, spray painting equipment, and the like. The direction and speed of the vehicle is remotely controlled by an operator via radio or wire.
Other types of crawlers employ suction to hold the device to the surface. These devices typically employ either a series of smaller suction devices mounted on endless tracks, or a larger suction device mounted on the frame of the device. This approach has the advantage of not being limited to ferrous surfaces. In addition, the suction can also be used to remove water and debris resulting from cleaning the surface. Such devices usually require a flexible skirt or partition to define a low pressure region between the crawler and the surface. However, normal wear and abrasion quickly damages the partition, so that some prior art devices are only capable of operation for a few hours before the partition must be replaced. Additionally, many prior art devices require extensive, time-consuming disassembly to replace the partition. All of this results in substantial expense and downtime to maintain the flexible partition.
The following list includes representative examples of the prior art in the field of crawlers used for removing coatings, cleaning, and painting:
______________________________________ Inventor Patent No. Issue Date ______________________________________ Gondert et al. 3,209,849 Oct. 5, 1965 DI Napoli 3,268,023 Aug. 23, 1966 Hammelmann 3,609,916 Oct. 5, 1971 Shino et al. 3,926,277 Dec. 16, 1975 Shio 3,960,229 June 1, 1976 Larsen 3,991,842 Nov. 16, 1976 Kneebone 4,789,037 Dec. 6, 1988 Hiraoka et al. 3,682,265 Aug. 8, 1972 Urakami 4,095,378 June 20, 1978 You 4,477,998 Oct. 23, 1984 Nagatsuka, et al. 4,664,212 May 12, 1987 Urakami 4,934,475 June 19,1990 Raviv et al. 4,971,591 Nov. 20, 1990 Urakami 5,007,210 Apr. 16, 1991 Urakami 5,014,803 May 14, 1991 Watkins et al. 5,285,601 Feb. 15, 1994 Urakami 5,536,199 July 16, 1996 Urakami 5,588,900 Dec. 31, 1996 Urakami 5,592,998 Jan. 14, 1997 ______________________________________
Gondert et al. disclose a towing vehicle that uses suction to increase traction between the vehicle and the supporting surface.
Di Napoli discloses a self-propelled load transport device that is supported on an air bearing.
Hammelmann discloses a cleaning apparatus for ships' hulls. Each working nozzle discharges jets of highly pressurized water through intercepting nozzles that create suction which counteracts the reaction forces and causes rollers to bear against the surface and maintain a predetermined minimum distance from the outlets of the intercepting nozzles.
Shino et al. disclose a vehicle having a hollow body that is drawn under suction against the surface over which the vehicle travels. Raviv et al. disclose another example of a vehicle with vacuum traction.
Nagatsuka et al. disclose a vacuum wall crawler having a pair of endless belts with a series of recesses that provide suction to hold the crawler to a wall. Larsen discloses another example of a vacuum wall crawler having an endless track with a series of cavities providing suction to hold the device to a surface.
Hiraoka et al. disclose a magnetic vehicle with a large central magnet and a series of lateral magnets. Kneebone, Shio, and Watkins et al. disclose other examples of magnetic tracked vehicles.
You discloses a wall-climbing toy having a series of suction disks mounted on an endless belt.
The Urakami '378 patent discloses a device capable of suction-adhering to a wall surface and moving along the wall. The device includes a rigid housing and a plurality of wheels or endless tracks for navigation. A flexible partition extending from the housing defines a substantially fluid-tight lower pressure area between the housing and surface.
The Urakami '475 and '210 patents disclose suction-adhering devices similar to that shown in the Urakami '378 patent, but also include vibration generating means (e.g., a piston and cylinder mechanism, or an eccentric weight secured to a rotating shaft) to move the device along the wall.
The Urakami '803 patent shows a suction-adhering device with a partitioning member 50 having an outer wall portion 54 and an inner wall portion 56. The pressure in the space within the partitioning member can be adjusted The partitioning member is apparently bolted to the frame of the device. The '803 patent mentions that the partitioning member can be formed of polyurethane rubber or synthetic resins. (column 3, lines 56-58).
The Urakami '199 patent discloses a suction-adhering device with a pair of oscillating frames. The embodiment illustrated in FIGS. 17 and 18 of the Urakami '199 patent regulates the pressure within the suction-adhering sealing means (suction ring) 80 as a function of the pressure measured within the enclosed housing 10.
The Urakami '900 patent discloses a suction-adhering device with a swivel bearing and crank mechanism carrying the cleaning nozzle.
The Urakami '998 patent shows a suction-adhering device with double-walled partitioning means 14 bolted to the frame, and a lower lip portion 106 that extends radially outward. The Urakami '998 patent also mentions that the partitioning means can be made of synthetic rubber such as urethane rubber (column 5, lines 45-47).
3. Solution to the Problem
None of the prior art references discussed above show a suction-adhering device with an inflatable suction ring that is held to the vehicle by friction fit around a cylindrical collar. This configuration permits the ring to be quickly and easily replaced in the field to minimize downtime.